The Second Edition of the Food Chemicals Codex (NAS-NRC Publ. ISBN 0-309-01949-4), published in August 1972, provides quality and purity specifications in monograph form for 639 substances used as food additives. The First Supplement to the Second Edition, published in April 1974, contains specifications for an additional 13 substances, plus 21 completely new general test methods and a number of miscellaneous revisions. The Second Supplement is scheduled for publication in mid-1975. Additional supplements are to be issued annually until the completely revised Third Edition of the Codex is published in 1977-78.